
You certainly picked a great place to help plan your upcoming Disney vacation and a great age to take your daughter for the first time!
There are a lot of things to consider when deciding if she's going to like an attraction or not! Is she adventurous? Does she like to try new things? Is she afraid of the dark? Loud noises?
The good thing about Disney is that they offer attractions to please every type of visitor. Fantasyland at MK is surely going to be hit, Nemo & Friends and The Seas at Epcot,
Pixar Place at HS, Rafiki's Planet Watch at AK. My DD is 3 and her favorite ride (aside from It's a Small World)? The Haunted Mansion. I didn't think she'd like it but we have a "try it once and if you don't like it, you don't have to ever ride it again" rule. It stands for almost all attractions except the obvious ones: ToT, RnRC, SM - basically anything with a bar or seat belt that is there to ensure she doesn't fly out.
As for transportation, definitely stick with Disney's. The buses run fairly on schedule and it's the easiest way to get to and from the parks when staying on property, in my opinion. Also, you can take the boat from POR to DTD as well as to POFQ, Riverside's sister resort and #2 on my list of favorites!